New update:
Version 2.0.1

Changelog:
+ Added a config file
+ Added the ability to open the GUI menu by pressing F on your keyboard (This can be enabled or disabled in the config)
+ Added some simple sound effects to some commands
+ Added /gm info command
+ Added /gm reload command (reloads the config in game)
+ Added the ability to give your admins or OPs a Gamemode item when they join the server
+ Added permissions into config
+ Added bug reporting option, clicking the link will open a ticket system using google forms.
+ Added a donation link for those who are generous

Fixes/Patches:
* Minor bug fixes and small patches were done in this update.
* Fixed the text when selecting your gamemode through the GUI.
* Changed color of "Your gamemode has been changed to (Survival)"

Note: I am still working on the ability to change other players gamemodes through the GUI menu, this is a big work in progress.